Reid filed a motion to “table” the amendment, a move that he used to quickly push for an up-or-down vote. A vote in favor of tabling the amendment would kill it. A vote against tabling the amendment would allow it to move through for debate. Essentially, a vote for Reid’s motion is a vote against securing the border before amnesty. Likewise, a vote against Reid’s motion is a vote for securing the border before granting amnesty.

The Senate Reference guide describes a motion to table as: “The motion is used to dispose quickly of questions the Senate does not wish to consider further.”

Reid’s decision to derail an open process on the immigration bill comes during the first week of debate on what will likely drag on until close to the Fourth of July recess. Losing Grassley’s support up front on process is dangerous for Reid, too, as Grassley is a key Republican leader on issues that involve immigration.

On the floor on Thursday, Grassley argued that the “so-called open and fair process” the Democrats and the “Gang of Eight” Republicans have promised “is a farce.”

“This is not the right way to start off on a very important bill,” Grassley said.